Car-brake



(No Model.)

ILSQHOPPBR GAR BRAKE.

No. 417,246. Patented Deg. 17, 18189.

(1] 11'\ P ['5 he lllllll ll \llll WITNESSES UNITED STATES PATENT OFFICE.

HENRY S. HOPPER, OF DETROIT, MICHIGAN.

C A R B RA K E SPECIFICATION forming part of Letters Patent No. 417,246, dated December 17, 1889.

Application filed May 14, 1889. Serial No. 310,746. (No model.)

To all whom it may concern.-

Be it known that I, HENRY S. HOPPER, a citizen of the United States, residing at Detroit, county of Wayne, State of Michigan, have invented certain new and useful Improvements in Take-Up Mechanism for Oar-Brakes and I declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to certain new and useful improvements in car-brakes, but more particularly to a device for automatically adjusting the brake mechanism to take up the wear upon the brake-shoes and the wheels.

\Vith car-brakes as ordinarily constructed it is necessary every few days for an attendant to go under the car and tighten up the parts by hand, so as to compensate for the wear upon the brake-shoes and the wheels. This operation necessarily consumes much time and labor, besides being disagreeable and sometimes dangerous work.

It is the object of this invention to provide means whereby the brake mechanism shall be automatically adjusted to take up this wear as fast as the wear takes place, without the necessity of any attention, thus insuring uni- 'formly perfect operation of the brakes at all times.

The various features of my invention will be more fully described in the following specification and claims, reference being made to the accompanying drawings, in which- Figure 1 is a view of an ordinary air-brake mechanism with myimproved take-up device attached thereto, showing the positions of the parts when the pressure is off the brake. Fig. 2 is a similar View showing the position which the parts would assume when the pressure is being exerted by the brakes upon the wheels. Fig. 3 is a section on line 00 a', Fig. 1. Fig. 4 is an elevation of the take-up mechanism.

A represents any ordinary actuating mechanismas, for instance, an air-brake cylinder, as shown in the drawings.

B represents the piston of the air-brake connected with the lever 0; this lever with the brake-rod D. At the extremity of said lever O, I provide a suitable ratchet-wheel E,

journaled upon and traveling with the said lever O. I also provide, in the extremity of the lever O, a slot 0, preferably at right angles to the said lever C. The ratchet-wheel E is formed with a suitable ca1n-slot, preferably of the form shown in the drawings ate, so arranged that it will be substantially at right angles to the said slot 0. The brakerod D is preferably bifurcated, as shown in the drawings, Fig. 3, and provided with perforations d, to admit the pin F, which forms a pivotal connection between the brake-rod and the lever O.

G represents a suitable spring-actuated pawl, secured to the lever O and adapted to hold the ratchet-wheel Ean d prevent it from turning backward.

H is a suitable spring-pawl attached to some immovable portion of the car-frame. h is a suitable set-screw to adjust said springpawl H, and h is a suitable locking-screw to secure said spring-paw]. in place.

By reference to the drawings it will be observed that the position of the pin F is determined by the location of the point of intersection of the slots 0 and e, the said pin being passed through both of said slots and through the perforations (Z in the end of the brake-rod, as shown in Figs. 3 and 4, to form connection between the brake-rod and the lever C. It will also be observed that the rotation of the ratchet-wheel E will cause the pin to travel farther from or nearer to the center of the said ratchet-wheel, according to the direction of the rotation of the said wheel. Now, suppose that the mechanism has been adjusted so as to operate properly and to bring the brake-shoes to a firm bearing upon the peripheries of the wheels. It is obvious that as the brake-shoes wear, their bearing against the wheels will become less and less firm, until they are practically of no effect in stopping the car. It will also be seen that as the brake-shoes wear, the throw of the lever C before the brake-shoes engage the wheels is increased in proportion to the amount of such wear upon the shoes. It will be readily seen that as the wear increases so as to permit the ratchet-wheel E to pass the point of the pawl H the said pawl will engage the teeth of said ratchet-wheel, and as the brakepressure is released the said ratchet-wheel will be caused to revolve in the direction of the arrow, Fig. 2, thus moving the point of connection with the brakc-rodi. a, the point of intersection of the slots 0 and e-farther from the center of the wheel E, thus adj usting the mechanism so as to bring the brakeshoes nearer to the peripheries of the wheels, so that they will be caused to engage the wheels by the same amount of throw of the parts as in the first instance. It will thus be seen that as the wear takes place the mechanism is automatically adjusted to tighten the parts and take up the wear, thus maintaining the proper positions of the brake-shoes relative to the wheels.

This device, it is obvious, may be readily adapted for use in connection with any of the various forms of brake mechanism.

The form of the mechanism for making the adjustment of the parts may be variously modified, and any form of inclined plane or wedge for changing the position of the connection with the brake-rod may be used in place of the cam-slot in the wheel. (Shown in the drawings.)

Having thus described my invention, what I claim is 1. A take-up device for car-brakes, consisting of a ratchet-wheel journaled upon a suitable operating-lever and having an adjustable connection with thebrake-rod, and in connection therewith means whereby said ratchet may be caused to rotate, so as to adjust said point of connection with the brake-rod to take up the wear upon the brake-shoes and the wheels, substantially as described.

2. A take-up device for car-brakes, consisting of a brake-lever havinga movable connection with the brake-rod, and in connection therewith a ratchet-wheel j ournaled upon said brake-lever, and adapted to operate a suitable cam to adjust said movable connection between. the brake-lever and the brake-rod, to take up the wear upon the brake-shoes, substantially as described.

3. In a take-up device for car-brakes, the combination, with a spiral cam or wedge j ournaled upon a suitable operating-lever and controlling the connection between said lever and the brake-rod, of suitable means for rotating said cam so as to shorten said rod and take up the wear on the shoes and wheels, substantially as described.

t. In a car-brake mechanism, the combina-- tion, with the brake-lever having a ratchetwheel journaled thereon and having a suitable cam-groove in which the brake-rod is engaged, of .a pawl adapted to engage said ratchet-wheel to revolve the same and thus take up the slack, substantially as described.

In testimony whereof I sign this specification in the presence of two witnesses.

HENRY S. HOPPER. \Vitnesses:

JOHN E. WILEs, HARRY SCHELLENBERGER. 

